Balloons mounted on the distal ends of catheters are widely used in medical treatment. The balloon may be used to widen a vessel into which the catheter is inserted, open a blocked vessel and/or deliver a medical device to a body location among other uses. The medical balloon includes a central body section, which is typically tubular, opposite cone sections at opposite longitudinal ends of the body section, and opposite waist sections at opposite longitudinal ends of the balloon. In use, the uninflated balloon is delivered to a treatment location within a body lumen (e.g., a blood vessel) by tracking through an introducer sheath and exiting a distal end of the sheath to reach the treatment location. Once the uninflated balloon has reached the treatment location, fluid is delivered into the balloon, thereby expanding the outer circumference of the balloon (i.e., balloon is inflated). After treatment, the balloon is deflated and “pulled back” into the introducer sheath. The balloon catheter can then be withdrawn from the introducer sheath and the patient's body. It may be necessary or desired to re-introduce the balloon catheter into a body lumen, through the introducer sheath, to further treat the body lumen.
One known method of forming a medical balloon involves blow molding. In particular, the balloon is formed by radially expanding a segment of extruded polymer tubing, called a parison, in a mold. Balloons produced by radially expanding a parison typically have thicker waist sections and cone sections than the thickness of their body sections. The thicker cone sections may interfere with refolding of the balloon upon deflation (i.e., after treatment), which can make it difficult to pull the balloon back into the introducer sheath. This interference with re-folding may also make it difficult for the user to re-introduce the deflated balloon into the sheath after withdrawing the balloon catheter from the patient's body.